1. Field of the Invention
The present invention relates to wireless communication networks. More particularly, although not exclusively, the present invention relates to networks adapted to implement or operate according to the 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 36.331 version (v) 8.4.0, the entire disclosure of which is hereby incorporated by reference, and/or to User Equipment (UE) for use in such networks.
2. Description of the Related Art
The 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 36.331 version (v) 8.4.0 specifies a number of conditions, criteria or events in response to which User Equipment (UE) is triggered to send a measurement report to a network, such as an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN).
To operate in accordance with the 3GPP TS 36.331 v 8.4.0 specification, the UE is arranged/adapted to report measurement information in accordance with a measurement configuration, which is provided to the UE by the E-UTRAN, that is, the E-UTRAN provides a signal or signals containing the measurement configuration to the UE.
Generally, the measurement configuration tells the UE, inter alia, the conditions, criteria or events in response to which it should send a measurement report, that is, the measurement configuration tells the UE the “reporting criteria”. Further, the measurement configuration tells the UE what to measure when triggered to send a report. In other words, the measurement configuration tells the UE the measurement objects, which are the objects on which the UE should perform the measurements. Also, the measurement configuration tells the UE the format in which the measurement results should be sent. In other words, the measurement configuration tells the UE the reporting format, including the quantities that the UE should include in the measurement report and associated information, such as the number of cells to report.
These events, in response to which the UE should send a measurement report, include events A1, A2, A3, A4, A5, B1 and B2 as defined in Table 1 below. Here, “serving” refers to a currently serving cell, e.g., a cell with which the UE is in communication, and “neighbor” refers to a neighboring cell.
Table 1 shows the current definitions of these events in 3GPP TS 33.331 v 8.4.0. Table 1 defines these events in terms of entering and leaving conditions. The entering conditions define the circumstances under which an event is regarded as occurring, when the event was not previously occurring. In other words, the UE is triggered to send a measurement report when there is a change from the conditions specified in the “entering condition” column not being met to being met.
The “leaving conditions” specify the conditions under which each event is considered to be no longer occurring. Thus, the UE is triggered to send a measurement report when, after entering an event, the circumstances change and the relevant leaving condition is met.
In each case, the entering conditions and leaving conditions associated with the various events, which can be regarded as defining the measurement report triggering conditions, are defined using a plurality of parameters or variables including Ms, Mn, Ofn, Ocn, Ofs, Ocs, Hys, Off, Thresh, Thresh1, and Thresh2, where:                Ms denotes a measurement result of a serving cell,        Mn denotes a measurement result of a neighboring cell,        Ofn denotes a frequency specific offset of the frequency of the neighbor cell,        Ocn denotes a cell specific offset of the neighbor cell,        Ofs denotes a frequency specific offset of the serving frequency,        Ocs denotes a cell specific offset of the serving cell,        Hys denotes a hysteresis parameter for the respective event,        Off denotes an offset parameter for the respective event,        Thresh denotes a threshold parameter for the respective event,        Thresh1 denotes a threshold parameter for the respective event, and        Thresh2 denotes a threshold parameter for the respective event.        
Further information on these parameters or variables can be found at the end of this description, in an extract from 3GPP TS 36.331 v 8.4.0.